gcb: Move KMS keys to k8s-releng-prod GCP project

[justaugustus]

What type of PR is this?
/kind cleanup feature

What this PR does / why we need it:
Now that KMS usage has been documented in kubernetes/sig-release#1016, we should cutover our GCB configs to use KMS assets in the k8s-releng-prod GCP project.

Signed-off-by: Stephen Augustus saugustus@vmware.com

ref: #911, kubernetes/k8s.io#641

Special notes for your reviewer:
KMS decrypter access granted to the kubernetes-release-test GCB service account:

$ gcloud kms keys add-iam-policy-binding \
    encrypt-0 --location=global --keyring=release \
    --member=serviceAccount:648026197307@cloudbuild.gserviceaccount.com \
    --role=roles/cloudkms.cryptoKeyDecrypter

Updated IAM policy for key [encrypt-0].
bindings:
- members:
  - serviceAccount:117157742389@cloudbuild.gserviceaccount.com
  - serviceAccount:615281671549@cloudbuild.gserviceaccount.com
  - serviceAccount:648026197307@cloudbuild.gserviceaccount.com
  role: roles/cloudkms.cryptoKeyDecrypter
etag: BwWgakJY2PQ=
version: 1

Does this PR introduce a user-facing change?:

gcb: Move KMS keys to k8s-releng-prod GCP project

[k8s-ci-robot]

@justaugustus: Adding label: do-not-merge/blocked-paths because PR changes a protected file.

Reasons for blocking this PR:

[Changes to certain release tools can affect our ability to test, build, and release Kubernetes. This PR must be explicitly approved by SIG Release repo admins.]

• gcb/patch-announce/cloudbuild.yaml

• gcb/release/cloudbuild.yaml

• gcb/stage/cloudbuild.yaml

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[justaugustus]

Ready for review:
/assign @tpepper @cpanato @saschagrunert
cc: @kubernetes/release-engineering

[saschagrunert]

/lgtm
/hold
for more eyes

[cpanato]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cpanato, justaugustus, saschagrunert

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[justaugustus]

/hold cancel